Complete mitochondrial genome of Critically Endangered Blue-throated Macaw (Ara glaucogularis): its comparison with partial mitogenome of Scarlet Macaw (Ara macao)

The influence of molecular markers and methods on inferring the phylogenetic relationships between the representatives of the Arini (parrots, Psittaciformes), determined on the basis of their complete mitochondrial genomes

BACKGROUND

Conures are a morphologically diverse group of Neotropical parrots classified as members of the tribe Arini, which has recently been subjected to a taxonomic revision. The previously broadly defined Aratinga genus of this tribe has been split into the 'true' Aratinga and three additional genera, Eupsittula, Psittacara and Thectocercus. Popular markers used in the reconstruction of the parrots' phylogenies derive from mitochondrial DNA. However, current phylogenetic analyses seem to indicate conflicting relationships between Aratinga and other conures, and also among other Arini members. Therefore, it is not clear if the mtDNA phylogenies can reliably define the species tree. The inconsistencies may result from the variable evolution rate of the markers used or their weak phylogenetic signal. To resolve these controversies and to assess to what extent the phylogenetic relationships in the tribe Arini can be inferred from mitochondrial genomes, we compared representative Arini mitogenomes as well as examined the usefulness of the individual mitochondrial markers and the efficiency of various phylogenetic methods.

RESULTS

Single molecular markers produced inconsistent tree topologies, while different methods offered various topologies even for the same marker. A significant disagreement in these tree topologies occurred for cytb, nd2 and nd6 genes, which are commonly used in parrot phylogenies. The strongest phylogenetic signal was found in the control region and RNA genes. However, these markers cannot be used alone in inferring Arini phylogenies because they do not provide fully resolved trees. The most reliable phylogeny of the parrots under study is obtained only on the concatenated set of all mitochondrial markers. The analyses established significantly resolved relationships within the former Aratinga representatives and the main genera of the tribe Arini. Such mtDNA phylogeny can be in agreement with the species tree, owing to its match with synapomorphic features in plumage colouration.

CONCLUSIONS

Phylogenetic relationships inferred from single mitochondrial markers can be incorrect and contradictory. Therefore, such phylogenies should be considered with caution. Reliable results can be produced by concatenated sets of all or at least the majority of mitochondrial genes and the control region. The results advance a new view on the relationships among the main genera of Arini and resolve the inconsistencies between the taxa that were previously classified as the broadly defined genus Aratinga. Although gene and species trees do not always have to be consistent, the mtDNA phylogenies for Arini can reflect the species tree.

Complete mitochondrial genome of golden conure (Guaruba guarouba)

Arini tribe with 19 genera is the most diversified tribe of neotropical parrots. Six of them are classified as macaws and nine as conures. The presence of bare facial area distinguishes macaws from conures and other members of this tribe. However, such morphological division seems to be disputable as the smallest macaw (monotypic Diopsittaca genus) turned out to be more closely related to three monotypic conures genera (Guaruba, Leptosittaca, Thectocercus) than to other macaws. We sequenced the complete mitochondrial genome of Guaruba guarouba to enrich the resource of molecular markers for examination of phylogenetic relationships between macaws and conures.

Complete mitochondrial genome of Blue-headed Macaw (Primolius couloni): its comparison with mitogenome of Blue-throated Macaw (Ara glaucogularis)

Primolius is a genus of midsized Macaws comprising three species. Blue-headed Macaws (Primolius couloni) are native to eastern Peru, extreme western Brazil and north-western Bolivia. In this study, full mitochondrial genome of considered species was sequenced. It is 16,995 bp long and contains 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a control region. Its comparison with published Blue-throated Macaw (Ara glaucogularis) mitogenome revealed their high degree of identity. Primolius couloni mitogenome is the first complete genomic sequence of this genus. It will be indispensable to refine the phylogenetic relationships within the tribe Arini and will enrich the resource of markers for systematic, phylogenetic and population genetic studies.

Complete mitochondrial genome of Military Macaw (Ara militaris): its comparison with mitogenomes of two other Ara species

The Military Macaw is one of the eight species of the genus Ara. The genus is one of six genera, which form morphologically diverse group termed as Macaws. Parrots of this group differ in body size on demand of the genus and species. Six of Ara species are classified as large Macaws. Based on morphological similarities and differences, these species can be segregated into three pairs according to their plumage coloration. Representative mitochondrial genomes were sequenced only for A. glaucogularis (blue and yellow coloration) and A. macao (predominantly red/scarlet). Ara militaris is one of two predominantly green species and full mitochondrial genome of considered species was sequenced in this study. It's comparison with A. glaucogularis and A. macao mitogenomes revealed higher degree of identity between militaris and macao sequences than between militaris and glaucogularis mtDNAs. Ara militaris mitogenome will be indispensable to refine the phylogenetic relationships within Macaw group.

Complete mitochondrial genome of Red-bellied Macaw (Orthopsittaca manilata): its comparison with mitogenome of Blue-throated Macaw (Ara glaucogularis)

The Red-bellied Macaw (Orthopsittaca manilata) is a species of the monotypic genus Orthopsittaca. The genus is one of the six genera, which form morphologically diverse group termed as Macaws. Individuals of Orthopsittaca manilata species are found in extremely large Amazonian area of South America. In this study, full mitochondrial genome of considered species was sequenced. It is 16,985 bp long and contains 13 protein-coding genes, 2 rRNAs, 22 tRNAs and a control region. Its comparison with published Blue-throated Macaw (Ara glaucogularis) mitogenome revealed their high degree of identity. Presented Orthopsittaca manilata mitogenome is the first complete genomic sequence of this genus. It will enrich the resource of molecular markers for future examination of evolutionary diversification of Macaws. It will be also indispensable to refine the phylogenetic relationships within the tribe Arini.